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General Medicine

Phlebotomy

Phlebotomy describes the act of removing blood from a patient using a needle. This can be for the purposes of laboratory testing as a diagnostic tool to narrow down a differential or can be used therapeutically for certain conditions. This activity reviews the procedure of phlebotomy and its various clinical correlations. Objectives: Review the common anatomical locations for phlebotomy. Identify the indications for phlebotomy as a diagnostic tool. Summarize the indications for therapeutic phleb

v1 · Reviewed Nov 7, 2026 by Automated Clinical Reviewer (Strict Verbatim v1)
  • Specific attention should be paid to identify the patients who are afraid of blood testing or have a positive history of vasovagal attack during prior similar procedures, to be prepared with all means to take action for a mishap of a vagal syncope provocatively.
  • In terms of any discrepancy among the mentioned data, any blood sampling should be deferred till the issue is resolved.
  • Other studies have found that patient identification and improper tube labeling are the most likely errors.
  • Laboratory values: bilirubin, which is a breakdown product of red blood cells, circulates in the bloodstream in two forms - conjugated and unconjugated.
  • A blood sample from a heel poke hours after birth or after a high degree of clinical suspicion will reveal bilirubin levels to determine an appropriate course of action for treatment.
  • Blood draws can also be extremely useful for establishing a differential when anemia is suspected.
  • Values such as mean corpuscular volume, lactate dehydrogenase, reticulocyte count, and haptoglobin levels are a few of many that can help distinguish a variety of types of anemias for a seemingly similar clinical presentation.
  • blood testing can be critical for diagnosing pathologies of the heart, such as myocardial infarction.
  • Cardiac enzymes can be released into the bloodstream signifying damage to the heart.
  • Peripheral blood smear (PBS): Peripheral blood smears are essential in the diagnosis of anemia.
  • By analyzing a thin layer of blood under a microscope, accurate analysis of RBC shape, color, size, and other morphologies can help establish a differential for the various causes of why a patient can be anemic.
  • A peripheral blood smear can also aid in the diagnosis of disordered affecting platelet quantity and morphology.
  • Additionally, leukocytosis is prevalent in peripheral blood smear analysis requiring further workup to determine if the finding is incidental or results from a malignant cause such as leukemia.
  • Therapeutic phlebotomy is the primary treatment of choice for Polycythemia Vera and results in improved symptoms and clinical outcomes by reducing the overall quantity of blood.
  • Therapeutic phlebotomy is the treatment of choice.
  • Thus, research shows that phlebotomy is an excellent treatment option by reducing iron stores.
  • These conditions require additional research and trials before being accepted as appropriate treatments, but initial trials show potential for improved clinical outcomes.
  • Conditions such as cellulitis or an abscess can increase the risk of bacteria directly infiltrating the blood.
  • Other contraindications for phlebotomy procedures include the presence of a vascular graft, a hematoma, venous fibrosis on palpation, a history of ipsilateral radical mastectomy, and any device used for venous access such as a venous port, central catheter, or an intravenous catheter.
  • Studies suggest that phlebotomy can be an inappropriate treatment for non-hereditary mutation association etiologies of hyperferritinemia leading to complications such as iron deficiency anemia and fatigue.
  • In terms of location, previously attempted sites with residual scar tissue are a contraindication.
  • In case of severe history of panic attacks during the procedure, the patient might be asked to lie down.
  • The patients who are planned to undergo the procedure in an office-based setting should be advised to stay in a sitting position for at least 15 minutes before initiating the procedure.
  • Alcoholic drinks should not be taken within 24 hours of the procedure, and all non-emergent medications should be avoided.
  • Wearing sterile gloves is mandatory while planning for obtaining blood cultures.
  • The tourniquet should be removed within 1 minute of placement.
  • Prolonged constriction of veins with the tourniquet can result in hemoconcentration, which is falsely elevated lab results.
  • The formation of a hematoma can also occur if adequate pressure is not applied during and after needle draw.
  • These complications can almost entirely be avoided with the proper technique and equipment.
  • From diagnosing various conditions, checking electrolytes levels repeatedly for tweaking management protocols, to treating patients afflicted with certain conditions, phlebotomy has an important role in improving clinical outcomes and serving as the bridge between the laboratory and the patient.
  • Health care providers must be knowledgeable about the patient's medical history and any preexisting conditions.
  • Health care providers should also be aware of the potential complications phlebotomy can present with and only perform when necessary.
  • The entire healthcare team of nurses, physicians, lab technicians, and phlebotomists are equally responsible for complete sterility throughout the procedure.
  • review
    Phlebotomy. StatPearls [Internet] — Kishan K. Srikanth, Saran Lotfollahzadeh — StatPearls Publishing, 2023

Decision support only. Verify against local protocols and current labeling. Source: www.ncbi.nlm.nih.gov